Cervicomedullary Exophytic Glioma

Focal lesion in lower medulla and upper cervical cord in region of formamen magnum and cervicomedullary junction posteriorly with evidence of sepatation and hypointense signal on T1 weighted images and hyperintense on T2 /FLAIR images.  There is cord thinning and altered signal intensity in the anteriorly placed cord tissue. These findings are consistent with diagnosis of exophytic cervicomedullary junction cystic glioma. Cervicomedullary glioma variants arise from upper cervical cord, with typical rostal extension into the cervicomedullary junction. The rostal extension is limited anteriorly by the pyramidal decussations; thus the mass expands posteriorly at the level of the obex and may rupture into the fourth ventricle. The caudal part is identical to an intramedullary tumor.